// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2010 Gael Guennebaud <gael.guennebaud@inria.fr>
// Copyright (C) 2010 Konstantinos Margaritis <markos@freevec.org>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef EIGEN_COMPLEX_NEON_H
#define EIGEN_COMPLEX_NEON_H

namespace Eigen {

namespace internal {

inline uint32x4_t
p4ui_CONJ_XOR()
{
// See bug 1325, clang fails to call vld1q_u64.
#if EIGEN_COMP_CLANG || EIGEN_COMP_CASTXML
	uint32x4_t ret = { 0x00000000, 0x80000000, 0x00000000, 0x80000000 };
	return ret;
#else
	static const uint32_t conj_XOR_DATA[] = { 0x00000000, 0x80000000, 0x00000000, 0x80000000 };
	return vld1q_u32(conj_XOR_DATA);
#endif
}

inline uint32x2_t
p2ui_CONJ_XOR()
{
	static const uint32_t conj_XOR_DATA[] = { 0x00000000, 0x80000000 };
	return vld1_u32(conj_XOR_DATA);
}

//---------- float ----------

struct Packet1cf
{
	EIGEN_STRONG_INLINE Packet1cf() {}
	EIGEN_STRONG_INLINE explicit Packet1cf(const Packet2f& a)
		: v(a)
	{
	}
	Packet2f v;
};
struct Packet2cf
{
	EIGEN_STRONG_INLINE Packet2cf() {}
	EIGEN_STRONG_INLINE explicit Packet2cf(const Packet4f& a)
		: v(a)
	{
	}
	Packet4f v;
};

template<>
struct packet_traits<std::complex<float>> : default_packet_traits
{
	typedef Packet2cf type;
	typedef Packet1cf half;
	enum
	{
		Vectorizable = 1,
		AlignedOnScalar = 1,
		size = 2,
		HasHalfPacket = 1,

		HasAdd = 1,
		HasSub = 1,
		HasMul = 1,
		HasDiv = 1,
		HasNegate = 1,
		HasAbs = 0,
		HasAbs2 = 0,
		HasMin = 0,
		HasMax = 0,
		HasSetLinear = 0
	};
};

template<>
struct unpacket_traits<Packet1cf>
{
	typedef std::complex<float> type;
	typedef Packet1cf half;
	typedef Packet2f as_real;
	enum
	{
		size = 1,
		alignment = Aligned16,
		vectorizable = true,
		masked_load_available = false,
		masked_store_available = false
	};
};
template<>
struct unpacket_traits<Packet2cf>
{
	typedef std::complex<float> type;
	typedef Packet1cf half;
	typedef Packet4f as_real;
	enum
	{
		size = 2,
		alignment = Aligned16,
		vectorizable = true,
		masked_load_available = false,
		masked_store_available = false
	};
};

template<>
EIGEN_STRONG_INLINE Packet1cf
pcast<float, Packet1cf>(const float& a)
{
	return Packet1cf(vset_lane_f32(a, vdup_n_f32(0.f), 0));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pcast<Packet2f, Packet2cf>(const Packet2f& a)
{
	return Packet2cf(vreinterpretq_f32_u64(vmovl_u32(vreinterpret_u32_f32(a))));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pset1<Packet1cf>(const std::complex<float>& from)
{
	return Packet1cf(vld1_f32(reinterpret_cast<const float*>(&from)));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pset1<Packet2cf>(const std::complex<float>& from)
{
	const float32x2_t r64 = vld1_f32(reinterpret_cast<const float*>(&from));
	return Packet2cf(vcombine_f32(r64, r64));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
padd<Packet1cf>(const Packet1cf& a, const Packet1cf& b)
{
	return Packet1cf(padd<Packet2f>(a.v, b.v));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
padd<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
{
	return Packet2cf(padd<Packet4f>(a.v, b.v));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
psub<Packet1cf>(const Packet1cf& a, const Packet1cf& b)
{
	return Packet1cf(psub<Packet2f>(a.v, b.v));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
psub<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
{
	return Packet2cf(psub<Packet4f>(a.v, b.v));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pnegate(const Packet1cf& a)
{
	return Packet1cf(pnegate<Packet2f>(a.v));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pnegate(const Packet2cf& a)
{
	return Packet2cf(pnegate<Packet4f>(a.v));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pconj(const Packet1cf& a)
{
	const Packet2ui b = vreinterpret_u32_f32(a.v);
	return Packet1cf(vreinterpret_f32_u32(veor_u32(b, p2ui_CONJ_XOR())));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pconj(const Packet2cf& a)
{
	const Packet4ui b = vreinterpretq_u32_f32(a.v);
	return Packet2cf(vreinterpretq_f32_u32(veorq_u32(b, p4ui_CONJ_XOR())));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pmul<Packet1cf>(const Packet1cf& a, const Packet1cf& b)
{
	Packet2f v1, v2;

	// Get the real values of a | a1_re | a1_re |
	v1 = vdup_lane_f32(a.v, 0);
	// Get the imag values of a | a1_im | a1_im |
	v2 = vdup_lane_f32(a.v, 1);
	// Multiply the real a with b
	v1 = vmul_f32(v1, b.v);
	// Multiply the imag a with b
	v2 = vmul_f32(v2, b.v);
	// Conjugate v2
	v2 = vreinterpret_f32_u32(veor_u32(vreinterpret_u32_f32(v2), p2ui_CONJ_XOR()));
	// Swap real/imag elements in v2.
	v2 = vrev64_f32(v2);
	// Add and return the result
	return Packet1cf(vadd_f32(v1, v2));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pmul<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
{
	Packet4f v1, v2;

	// Get the real values of a | a1_re | a1_re | a2_re | a2_re |
	v1 = vcombine_f32(vdup_lane_f32(vget_low_f32(a.v), 0), vdup_lane_f32(vget_high_f32(a.v), 0));
	// Get the imag values of a | a1_im | a1_im | a2_im | a2_im |
	v2 = vcombine_f32(vdup_lane_f32(vget_low_f32(a.v), 1), vdup_lane_f32(vget_high_f32(a.v), 1));
	// Multiply the real a with b
	v1 = vmulq_f32(v1, b.v);
	// Multiply the imag a with b
	v2 = vmulq_f32(v2, b.v);
	// Conjugate v2
	v2 = vreinterpretq_f32_u32(veorq_u32(vreinterpretq_u32_f32(v2), p4ui_CONJ_XOR()));
	// Swap real/imag elements in v2.
	v2 = vrev64q_f32(v2);
	// Add and return the result
	return Packet2cf(vaddq_f32(v1, v2));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pcmp_eq(const Packet1cf& a, const Packet1cf& b)
{
	// Compare real and imaginary parts of a and b to get the mask vector:
	// [re(a[0])==re(b[0]), im(a[0])==im(b[0])]
	Packet2f eq = pcmp_eq<Packet2f>(a.v, b.v);
	// Swap real/imag elements in the mask in to get:
	// [im(a[0])==im(b[0]), re(a[0])==re(b[0])]
	Packet2f eq_swapped = vrev64_f32(eq);
	// Return re(a)==re(b) && im(a)==im(b) by computing bitwise AND of eq and eq_swapped
	return Packet1cf(pand<Packet2f>(eq, eq_swapped));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pcmp_eq(const Packet2cf& a, const Packet2cf& b)
{
	// Compare real and imaginary parts of a and b to get the mask vector:
	// [re(a[0])==re(b[0]), im(a[0])==im(b[0]), re(a[1])==re(b[1]), im(a[1])==im(b[1])]
	Packet4f eq = pcmp_eq<Packet4f>(a.v, b.v);
	// Swap real/imag elements in the mask in to get:
	// [im(a[0])==im(b[0]), re(a[0])==re(b[0]), im(a[1])==im(b[1]), re(a[1])==re(b[1])]
	Packet4f eq_swapped = vrev64q_f32(eq);
	// Return re(a)==re(b) && im(a)==im(b) by computing bitwise AND of eq and eq_swapped
	return Packet2cf(pand<Packet4f>(eq, eq_swapped));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pand<Packet1cf>(const Packet1cf& a, const Packet1cf& b)
{
	return Packet1cf(vreinterpret_f32_u32(vand_u32(vreinterpret_u32_f32(a.v), vreinterpret_u32_f32(b.v))));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pand<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
{
	return Packet2cf(vreinterpretq_f32_u32(vandq_u32(vreinterpretq_u32_f32(a.v), vreinterpretq_u32_f32(b.v))));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
por<Packet1cf>(const Packet1cf& a, const Packet1cf& b)
{
	return Packet1cf(vreinterpret_f32_u32(vorr_u32(vreinterpret_u32_f32(a.v), vreinterpret_u32_f32(b.v))));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
por<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
{
	return Packet2cf(vreinterpretq_f32_u32(vorrq_u32(vreinterpretq_u32_f32(a.v), vreinterpretq_u32_f32(b.v))));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pxor<Packet1cf>(const Packet1cf& a, const Packet1cf& b)
{
	return Packet1cf(vreinterpret_f32_u32(veor_u32(vreinterpret_u32_f32(a.v), vreinterpret_u32_f32(b.v))));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pxor<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
{
	return Packet2cf(vreinterpretq_f32_u32(veorq_u32(vreinterpretq_u32_f32(a.v), vreinterpretq_u32_f32(b.v))));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pandnot<Packet1cf>(const Packet1cf& a, const Packet1cf& b)
{
	return Packet1cf(vreinterpret_f32_u32(vbic_u32(vreinterpret_u32_f32(a.v), vreinterpret_u32_f32(b.v))));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pandnot<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
{
	return Packet2cf(vreinterpretq_f32_u32(vbicq_u32(vreinterpretq_u32_f32(a.v), vreinterpretq_u32_f32(b.v))));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pload<Packet1cf>(const std::complex<float>* from)
{
	EIGEN_DEBUG_ALIGNED_LOAD return Packet1cf(pload<Packet2f>((const float*)from));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pload<Packet2cf>(const std::complex<float>* from)
{
	EIGEN_DEBUG_ALIGNED_LOAD return Packet2cf(pload<Packet4f>(reinterpret_cast<const float*>(from)));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
ploadu<Packet1cf>(const std::complex<float>* from)
{
	EIGEN_DEBUG_UNALIGNED_LOAD return Packet1cf(ploadu<Packet2f>((const float*)from));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
ploadu<Packet2cf>(const std::complex<float>* from)
{
	EIGEN_DEBUG_UNALIGNED_LOAD return Packet2cf(ploadu<Packet4f>(reinterpret_cast<const float*>(from)));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
ploaddup<Packet1cf>(const std::complex<float>* from)
{
	return pset1<Packet1cf>(*from);
}
template<>
EIGEN_STRONG_INLINE Packet2cf
ploaddup<Packet2cf>(const std::complex<float>* from)
{
	return pset1<Packet2cf>(*from);
}

template<>
EIGEN_STRONG_INLINE void
pstore<std::complex<float>>(std::complex<float>* to, const Packet1cf& from)
{
	EIGEN_DEBUG_ALIGNED_STORE pstore((float*)to, from.v);
}
template<>
EIGEN_STRONG_INLINE void
pstore<std::complex<float>>(std::complex<float>* to, const Packet2cf& from)
{
	EIGEN_DEBUG_ALIGNED_STORE pstore(reinterpret_cast<float*>(to), from.v);
}

template<>
EIGEN_STRONG_INLINE void
pstoreu<std::complex<float>>(std::complex<float>* to, const Packet1cf& from)
{
	EIGEN_DEBUG_UNALIGNED_STORE pstoreu((float*)to, from.v);
}
template<>
EIGEN_STRONG_INLINE void
pstoreu<std::complex<float>>(std::complex<float>* to, const Packet2cf& from)
{
	EIGEN_DEBUG_UNALIGNED_STORE pstoreu(reinterpret_cast<float*>(to), from.v);
}

template<>
EIGEN_DEVICE_FUNC inline Packet1cf
pgather<std::complex<float>, Packet1cf>(const std::complex<float>* from, Index stride)
{
	const Packet2f tmp = vdup_n_f32(std::real(from[0 * stride]));
	return Packet1cf(vset_lane_f32(std::imag(from[0 * stride]), tmp, 1));
}
template<>
EIGEN_DEVICE_FUNC inline Packet2cf
pgather<std::complex<float>, Packet2cf>(const std::complex<float>* from, Index stride)
{
	Packet4f res = vdupq_n_f32(std::real(from[0 * stride]));
	res = vsetq_lane_f32(std::imag(from[0 * stride]), res, 1);
	res = vsetq_lane_f32(std::real(from[1 * stride]), res, 2);
	res = vsetq_lane_f32(std::imag(from[1 * stride]), res, 3);
	return Packet2cf(res);
}

template<>
EIGEN_DEVICE_FUNC inline void
pscatter<std::complex<float>, Packet1cf>(std::complex<float>* to, const Packet1cf& from, Index stride)
{
	to[stride * 0] = std::complex<float>(vget_lane_f32(from.v, 0), vget_lane_f32(from.v, 1));
}
template<>
EIGEN_DEVICE_FUNC inline void
pscatter<std::complex<float>, Packet2cf>(std::complex<float>* to, const Packet2cf& from, Index stride)
{
	to[stride * 0] = std::complex<float>(vgetq_lane_f32(from.v, 0), vgetq_lane_f32(from.v, 1));
	to[stride * 1] = std::complex<float>(vgetq_lane_f32(from.v, 2), vgetq_lane_f32(from.v, 3));
}

template<>
EIGEN_STRONG_INLINE void
prefetch<std::complex<float>>(const std::complex<float>* addr)
{
	EIGEN_ARM_PREFETCH(reinterpret_cast<const float*>(addr));
}

template<>
EIGEN_STRONG_INLINE std::complex<float>
pfirst<Packet1cf>(const Packet1cf& a)
{
	EIGEN_ALIGN16 std::complex<float> x;
	vst1_f32(reinterpret_cast<float*>(&x), a.v);
	return x;
}
template<>
EIGEN_STRONG_INLINE std::complex<float>
pfirst<Packet2cf>(const Packet2cf& a)
{
	EIGEN_ALIGN16 std::complex<float> x[2];
	vst1q_f32(reinterpret_cast<float*>(x), a.v);
	return x[0];
}

template<>
EIGEN_STRONG_INLINE Packet1cf
preverse(const Packet1cf& a)
{
	return a;
}
template<>
EIGEN_STRONG_INLINE Packet2cf
preverse(const Packet2cf& a)
{
	return Packet2cf(vcombine_f32(vget_high_f32(a.v), vget_low_f32(a.v)));
}

template<>
EIGEN_STRONG_INLINE Packet1cf
pcplxflip<Packet1cf>(const Packet1cf& a)
{
	return Packet1cf(vrev64_f32(a.v));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pcplxflip<Packet2cf>(const Packet2cf& a)
{
	return Packet2cf(vrev64q_f32(a.v));
}

template<>
EIGEN_STRONG_INLINE std::complex<float>
predux<Packet1cf>(const Packet1cf& a)
{
	std::complex<float> s;
	vst1_f32((float*)&s, a.v);
	return s;
}
template<>
EIGEN_STRONG_INLINE std::complex<float>
predux<Packet2cf>(const Packet2cf& a)
{
	std::complex<float> s;
	vst1_f32(reinterpret_cast<float*>(&s), vadd_f32(vget_low_f32(a.v), vget_high_f32(a.v)));
	return s;
}

template<>
EIGEN_STRONG_INLINE std::complex<float>
predux_mul<Packet1cf>(const Packet1cf& a)
{
	std::complex<float> s;
	vst1_f32((float*)&s, a.v);
	return s;
}
template<>
EIGEN_STRONG_INLINE std::complex<float>
predux_mul<Packet2cf>(const Packet2cf& a)
{
	float32x2_t a1, a2, v1, v2, prod;
	std::complex<float> s;

	a1 = vget_low_f32(a.v);
	a2 = vget_high_f32(a.v);
	// Get the real values of a | a1_re | a1_re | a2_re | a2_re |
	v1 = vdup_lane_f32(a1, 0);
	// Get the real values of a | a1_im | a1_im | a2_im | a2_im |
	v2 = vdup_lane_f32(a1, 1);
	// Multiply the real a with b
	v1 = vmul_f32(v1, a2);
	// Multiply the imag a with b
	v2 = vmul_f32(v2, a2);
	// Conjugate v2
	v2 = vreinterpret_f32_u32(veor_u32(vreinterpret_u32_f32(v2), p2ui_CONJ_XOR()));
	// Swap real/imag elements in v2.
	v2 = vrev64_f32(v2);
	// Add v1, v2
	prod = vadd_f32(v1, v2);

	vst1_f32(reinterpret_cast<float*>(&s), prod);

	return s;
}

EIGEN_MAKE_CONJ_HELPER_CPLX_REAL(Packet1cf, Packet2f)
EIGEN_MAKE_CONJ_HELPER_CPLX_REAL(Packet2cf, Packet4f)

template<>
EIGEN_STRONG_INLINE Packet1cf
pdiv<Packet1cf>(const Packet1cf& a, const Packet1cf& b)
{
	// TODO optimize it for NEON
	Packet1cf res = pmul(a, pconj(b));
	Packet2f s, rev_s;

	// this computes the norm
	s = vmul_f32(b.v, b.v);
	rev_s = vrev64_f32(s);

	return Packet1cf(pdiv<Packet2f>(res.v, vadd_f32(s, rev_s)));
}
template<>
EIGEN_STRONG_INLINE Packet2cf
pdiv<Packet2cf>(const Packet2cf& a, const Packet2cf& b)
{
	// TODO optimize it for NEON
	Packet2cf res = pmul(a, pconj(b));
	Packet4f s, rev_s;

	// this computes the norm
	s = vmulq_f32(b.v, b.v);
	rev_s = vrev64q_f32(s);

	return Packet2cf(pdiv<Packet4f>(res.v, vaddq_f32(s, rev_s)));
}

EIGEN_DEVICE_FUNC inline void
ptranspose(PacketBlock<Packet1cf, 1>& /*kernel*/)
{
}
EIGEN_DEVICE_FUNC inline void
ptranspose(PacketBlock<Packet2cf, 2>& kernel)
{
	Packet4f tmp = vcombine_f32(vget_high_f32(kernel.packet[0].v), vget_high_f32(kernel.packet[1].v));
	kernel.packet[0].v = vcombine_f32(vget_low_f32(kernel.packet[0].v), vget_low_f32(kernel.packet[1].v));
	kernel.packet[1].v = tmp;
}

template<>
EIGEN_STRONG_INLINE Packet1cf
psqrt<Packet1cf>(const Packet1cf& a)
{
	return psqrt_complex<Packet1cf>(a);
}

template<>
EIGEN_STRONG_INLINE Packet2cf
psqrt<Packet2cf>(const Packet2cf& a)
{
	return psqrt_complex<Packet2cf>(a);
}

//---------- double ----------
#if EIGEN_ARCH_ARM64 && !EIGEN_APPLE_DOUBLE_NEON_BUG

// See bug 1325, clang fails to call vld1q_u64.
#if EIGEN_COMP_CLANG || EIGEN_COMP_CASTXML
static uint64x2_t p2ul_CONJ_XOR = { 0x0, 0x8000000000000000 };
#else
const uint64_t p2ul_conj_XOR_DATA[] = { 0x0, 0x8000000000000000 };
static uint64x2_t p2ul_CONJ_XOR = vld1q_u64(p2ul_conj_XOR_DATA);
#endif

struct Packet1cd
{
	EIGEN_STRONG_INLINE Packet1cd() {}
	EIGEN_STRONG_INLINE explicit Packet1cd(const Packet2d& a)
		: v(a)
	{
	}
	Packet2d v;
};

template<>
struct packet_traits<std::complex<double>> : default_packet_traits
{
	typedef Packet1cd type;
	typedef Packet1cd half;
	enum
	{
		Vectorizable = 1,
		AlignedOnScalar = 0,
		size = 1,
		HasHalfPacket = 0,

		HasAdd = 1,
		HasSub = 1,
		HasMul = 1,
		HasDiv = 1,
		HasNegate = 1,
		HasAbs = 0,
		HasAbs2 = 0,
		HasMin = 0,
		HasMax = 0,
		HasSetLinear = 0
	};
};

template<>
struct unpacket_traits<Packet1cd>
{
	typedef std::complex<double> type;
	typedef Packet1cd half;
	typedef Packet2d as_real;
	enum
	{
		size = 1,
		alignment = Aligned16,
		vectorizable = true,
		masked_load_available = false,
		masked_store_available = false
	};
};

template<>
EIGEN_STRONG_INLINE Packet1cd
pload<Packet1cd>(const std::complex<double>* from)
{
	EIGEN_DEBUG_ALIGNED_LOAD return Packet1cd(pload<Packet2d>(reinterpret_cast<const double*>(from)));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
ploadu<Packet1cd>(const std::complex<double>* from)
{
	EIGEN_DEBUG_UNALIGNED_LOAD return Packet1cd(ploadu<Packet2d>(reinterpret_cast<const double*>(from)));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
pset1<Packet1cd>(const std::complex<double>& from)
{
	/* here we really have to use unaligned loads :( */
	return ploadu<Packet1cd>(&from);
}

template<>
EIGEN_STRONG_INLINE Packet1cd
padd<Packet1cd>(const Packet1cd& a, const Packet1cd& b)
{
	return Packet1cd(padd<Packet2d>(a.v, b.v));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
psub<Packet1cd>(const Packet1cd& a, const Packet1cd& b)
{
	return Packet1cd(psub<Packet2d>(a.v, b.v));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
pnegate(const Packet1cd& a)
{
	return Packet1cd(pnegate<Packet2d>(a.v));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
pconj(const Packet1cd& a)
{
	return Packet1cd(vreinterpretq_f64_u64(veorq_u64(vreinterpretq_u64_f64(a.v), p2ul_CONJ_XOR)));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
pmul<Packet1cd>(const Packet1cd& a, const Packet1cd& b)
{
	Packet2d v1, v2;

	// Get the real values of a
	v1 = vdupq_lane_f64(vget_low_f64(a.v), 0);
	// Get the imag values of a
	v2 = vdupq_lane_f64(vget_high_f64(a.v), 0);
	// Multiply the real a with b
	v1 = vmulq_f64(v1, b.v);
	// Multiply the imag a with b
	v2 = vmulq_f64(v2, b.v);
	// Conjugate v2
	v2 = vreinterpretq_f64_u64(veorq_u64(vreinterpretq_u64_f64(v2), p2ul_CONJ_XOR));
	// Swap real/imag elements in v2.
	v2 = preverse<Packet2d>(v2);
	// Add and return the result
	return Packet1cd(vaddq_f64(v1, v2));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
pcmp_eq(const Packet1cd& a, const Packet1cd& b)
{
	// Compare real and imaginary parts of a and b to get the mask vector:
	// [re(a)==re(b), im(a)==im(b)]
	Packet2d eq = pcmp_eq<Packet2d>(a.v, b.v);
	// Swap real/imag elements in the mask in to get:
	// [im(a)==im(b), re(a)==re(b)]
	Packet2d eq_swapped = vreinterpretq_f64_u32(vrev64q_u32(vreinterpretq_u32_f64(eq)));
	// Return re(a)==re(b) & im(a)==im(b) by computing bitwise AND of eq and eq_swapped
	return Packet1cd(pand<Packet2d>(eq, eq_swapped));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
pand<Packet1cd>(const Packet1cd& a, const Packet1cd& b)
{
	return Packet1cd(vreinterpretq_f64_u64(vandq_u64(vreinterpretq_u64_f64(a.v), vreinterpretq_u64_f64(b.v))));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
por<Packet1cd>(const Packet1cd& a, const Packet1cd& b)
{
	return Packet1cd(vreinterpretq_f64_u64(vorrq_u64(vreinterpretq_u64_f64(a.v), vreinterpretq_u64_f64(b.v))));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
pxor<Packet1cd>(const Packet1cd& a, const Packet1cd& b)
{
	return Packet1cd(vreinterpretq_f64_u64(veorq_u64(vreinterpretq_u64_f64(a.v), vreinterpretq_u64_f64(b.v))));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
pandnot<Packet1cd>(const Packet1cd& a, const Packet1cd& b)
{
	return Packet1cd(vreinterpretq_f64_u64(vbicq_u64(vreinterpretq_u64_f64(a.v), vreinterpretq_u64_f64(b.v))));
}

template<>
EIGEN_STRONG_INLINE Packet1cd
ploaddup<Packet1cd>(const std::complex<double>* from)
{
	return pset1<Packet1cd>(*from);
}

template<>
EIGEN_STRONG_INLINE void
pstore<std::complex<double>>(std::complex<double>* to, const Packet1cd& from)
{
	EIGEN_DEBUG_ALIGNED_STORE pstore(reinterpret_cast<double*>(to), from.v);
}

template<>
EIGEN_STRONG_INLINE void
pstoreu<std::complex<double>>(std::complex<double>* to, const Packet1cd& from)
{
	EIGEN_DEBUG_UNALIGNED_STORE pstoreu(reinterpret_cast<double*>(to), from.v);
}

template<>
EIGEN_STRONG_INLINE void
prefetch<std::complex<double>>(const std::complex<double>* addr)
{
	EIGEN_ARM_PREFETCH(reinterpret_cast<const double*>(addr));
}

template<>
EIGEN_DEVICE_FUNC inline Packet1cd
pgather<std::complex<double>, Packet1cd>(const std::complex<double>* from, Index stride)
{
	Packet2d res = pset1<Packet2d>(0.0);
	res = vsetq_lane_f64(std::real(from[0 * stride]), res, 0);
	res = vsetq_lane_f64(std::imag(from[0 * stride]), res, 1);
	return Packet1cd(res);
}

template<>
EIGEN_DEVICE_FUNC inline void
pscatter<std::complex<double>, Packet1cd>(std::complex<double>* to, const Packet1cd& from, Index stride)
{
	to[stride * 0] = std::complex<double>(vgetq_lane_f64(from.v, 0), vgetq_lane_f64(from.v, 1));
}

template<>
EIGEN_STRONG_INLINE std::complex<double>
pfirst<Packet1cd>(const Packet1cd& a)
{
	EIGEN_ALIGN16 std::complex<double> res;
	pstore<std::complex<double>>(&res, a);
	return res;
}

template<>
EIGEN_STRONG_INLINE Packet1cd
preverse(const Packet1cd& a)
{
	return a;
}

template<>
EIGEN_STRONG_INLINE std::complex<double>
predux<Packet1cd>(const Packet1cd& a)
{
	return pfirst(a);
}

template<>
EIGEN_STRONG_INLINE std::complex<double>
predux_mul<Packet1cd>(const Packet1cd& a)
{
	return pfirst(a);
}

EIGEN_MAKE_CONJ_HELPER_CPLX_REAL(Packet1cd, Packet2d)

template<>
EIGEN_STRONG_INLINE Packet1cd
pdiv<Packet1cd>(const Packet1cd& a, const Packet1cd& b)
{
	// TODO optimize it for NEON
	Packet1cd res = pmul(a, pconj(b));
	Packet2d s = pmul<Packet2d>(b.v, b.v);
	Packet2d rev_s = preverse<Packet2d>(s);

	return Packet1cd(pdiv(res.v, padd<Packet2d>(s, rev_s)));
}

EIGEN_STRONG_INLINE Packet1cd pcplxflip /*<Packet1cd>*/ (const Packet1cd& x)
{
	return Packet1cd(preverse(Packet2d(x.v)));
}

EIGEN_STRONG_INLINE void
ptranspose(PacketBlock<Packet1cd, 2>& kernel)
{
	Packet2d tmp = vcombine_f64(vget_high_f64(kernel.packet[0].v), vget_high_f64(kernel.packet[1].v));
	kernel.packet[0].v = vcombine_f64(vget_low_f64(kernel.packet[0].v), vget_low_f64(kernel.packet[1].v));
	kernel.packet[1].v = tmp;
}

template<>
EIGEN_STRONG_INLINE Packet1cd
psqrt<Packet1cd>(const Packet1cd& a)
{
	return psqrt_complex<Packet1cd>(a);
}

#endif // EIGEN_ARCH_ARM64

} // end namespace internal

} // end namespace Eigen

#endif // EIGEN_COMPLEX_NEON_H
